WK Grand Cherokee Diesel

[alltrbo]

But CRD HEEP reads as crud heap which is a nicer way of saying crap heap so there is not a more fitting or complete description that you can fit into 7 letters and 1 space. It's a common rail diesel Jeep that is a crap heap.

[The Dark Side of Will]

Crud is an interesting interpretation.

[The Dark Side of Will]

Summit had Bilstein B8's for the rear for <$100 each, so I ordered a pair. That's a total overkill level of upgrade. I'm going from zero rear shocks to two rear shocks, so the percentage increase is infinite.

[The Dark Side of Will]

Pics to follow sometime...
Over the weekend I got the mismatched wheels off and installed stock base model GC Laredo wheels with stock size 245/65-17 Kumho RoadVenture AT51 tires. We had some problems with the "jacketed" lug nuts being overtightened, but overcame those by chiseling the jackets off.

I sent a pic to Alltrbo, who said it still looked high. I checked in the front wheel wells and find Rough Country's 2" spacer lift: https://www.roughcountry.com/jeep-suspe ... 4wd-736848
However, there are no spacers in the rear. It might have actual 2" lift springs there.

Also, Alltrbo noticed that the front wheels and tires are stock JK Rubicon fare. I'm now leaning toward keeping those two and snagging another pair to use for trail days, while keeping the Kumhos for bad weather city driving and mall crawling.

My dad and I diagnosed the fuel pump and found the fuses and relay all worked. I didn't find the production break above the rear U-joint in the rear driveshaft until later, so we have not actually checked that yet.
I spoke with a local mechanic who said he could do the fuel pump. After dealing with German cars that have fuel pump access hatches in the floorpan, having to drop the tank to change the fuel pump just seems like bullshit to me.
I decided I should drop the gas tank shield to help him out, as I wanted to pay him to get covered in diesel fuel, not worry old bolts out of the body. My point of reference was my dad decades ago installing a gas tank shield in his '79 Suburban, and then again a few years later when he got his current '90 Suburban. The tank had its own straps and the shield bolted in on top of it.
However, when the gas tank shield is standard equipment, OEM thinking is "Why do we need to buy extra straps?". Of course it wasn't until I pulled the next-to-last bolt and had the tank come down with the shield that I realized this. At that point I thought "Well the tank's coming down now!" Everything I was wearing that day now smells like diesel fuel.
Also, one of the 6x 12mm bolts holding the shield in broke. The shield had taken some abuse, too. One of its straps is twisted from being dragged over something and a spot weld is broken.
I'm thinking about having the local engine machine shop run the tank through their parts washer, and then POR-ing it. I'm also wondering how much effort I should put into cleaning up/preserving the shield before I put it back up. The crevice volume between the shield and tank is ripe for collecting dirt and mud that will retain water. The internet is full of stories of rusted tanks and shields.

The salvage yard had swapped the original giant diesel battery for a normal sized battery. I put a charger on it and it took a while to come up from 75%, so at least it seems to be in good shape. I'll have to price an AGM battery in the correct size and see if I want to throw down that kind of scratch.
So next weekend (after I put my Northstar short block together! ) I'll throw the battery back in it and check to verify there's voltage at the fuel pump connector above the rear axle

[The Dark Side of Will]

Here it is as delivered:
'15+ JK grey 10 slots on the front, WJ 16x7's on the rear. The front tires are 255/75-17's, which is the stock Rubicon size.



Totally quick/easy method of lifting a vehicle for 4x wheel/tire changes.
The right tine is under the transmission crossmember, which is really close to the vehicle's balance point. The vehicle's right frame rail on the left tine was air gapped and it didn't really want to get the left front off the ground. I ended up having to stand in the right rear wheel to get the left front off the ground.







The front lugs were overtightened. I started out with a 12 point socket, which ruined the jacketing on one lug each side to the point that we had to chisel the jacketing off to put a tool on the actual nut.



Clearance of the 255/75-17 to the tip of the front upper ball joint stud.



View showing it's still high in the front... Looking at this, I'm not sure the rear is lifted at all.



Diesel engine with the beauty cover removed. Is the fuel filter the barely visible round can in the middle?



Last time it was legal to drive in VA



Rough Country 2" spacer lift in the front



Fuel tank on its way out



And that's how the fuel tank do.

[The Dark Side of Will]

The CarQuest fuel pump was the wrong one. My dad found the right Mopar PN and I ordered it from a company called Herko in Miami... looks like it won't be here by the end of the week, though. That unit is rather difficult to find. Unfortunately it's not just the pump. As is the current trend in OEM design, the package is the entire sending unit, not just the pump. :-/

[The Dark Side of Will]

Fuel pump arrived yesterday, but I won't have time to mess with it until the weekend.
This entire assembly for $150 seems sketchy... I guess we'll see.

https://herko.com/productinfo.php?inv=25564

[ericjon262]

And that's how the fuel tank do.

LOL! I value my life too much to buy or use Harbor Freight jack stands.

hmmm... I seem to remember a particular brand of jackstands having that same color paint...

[The Dark Side of Will]

Ralph Lauren doesn't make jackstands... nobody has trademarked safety orange. I think that particular pair is older than Harbor Freight.

[ericjon262]

Ralph Lauren doesn't make jackstands... nobody has trademarked safety orange. I think that particular pair is older than Harbor Freight.

For a long while all of their material handling products were orange, but, as you say, they don't own a trademark on safety orange. Gotta try and catch ya somewhere! lol.

[The Dark Side of Will]

The fuel pump assembly did not come with an o-ring, so I had to source that. RockAuto lists it for $16, but can't get one until next week. CarQuest and O'Reilly's can get them immediately, but for $30. Must be a hell of an o-ring.
We put the new pump in temporarily with the old o-ring and my dad power washed the tank this week. I'll get a coat of POR or similar urethane paint on it this weekend and maybe even get it back in the vehicle.

I also ordered a new fuel filter. Having this vehicle and the Benz both with Benz powertrains is kind of fun... a lot of the controls are the same across the two... Same VNT turbo actuator, same glow plug controller, same fuel filter; I'm sure I'll find more. They have the same transmission as well, so all the stuff I'm about to do to the Benz for the 200,000 mile transmission service I'll end up doing to the Jeep also before too long.

[The Dark Side of Will]

I have my tank and tank shield out of my new-to-me '07 WK GC CRD to replace the fuel pump. Since they've been in the vehicle for 14 years and had some warts and ugly spots, I decided it was probably a good idea to clean them up and paint them with POR-15 to ensure they last another 14 or 15 years.

I installed the new pump along with a new Dorman 911-245 o-ring. This has a round section, while the old one coming out had a square section. RockAuto lists both the Dorman part and the Mopar part. The photo on RockAuto of the Mopar part shows a round cross-section o-ring, so I @$$ume the old part was originally round and took a set with the square cross section over time.

I turned the tank upside down to paint the bottom, as shown in the 2nd photo. There was maybe a gallon of fuel in the tank I had not been able to get out. I painted the bottom of the tank, left it for about 5 hours while the paint cured, then flipped it over to paint the top.
There was fuel residue/leakage around the fuel pump o-ring. I would not have expected this to happen. I would have expected that the fuel pump o-ring would create a fuel-tight seal that could be immersed in fuel with the tank upside down and still not leak.

Has anyone had a similar experience?
I was hoping to install the tank and drive the dam Jeep tomorrow, but now I'm wondering if I need to get an actual Mopar o-ring.
My dad and I will pull the lock ring and re-seat/re-seal the new o-ring tomorrow, but I'm not sure if there's anything else I can do.

Pics for attention:

[The Dark Side of Will]

This is the new o-ring vs. the original. The original has a square cross section, with a groove in the middle of each sealing face, resulting in two high pressure locations (inner & outer), which is effectively a double seal. The photos on RockAuto show a round cross-section o-ring... Next stop: dealership to see what's up.



At least the pump I bought appears to be a Bosch part.



Sooo... In all my experience with GM fuel pumps, there's always been a "sock" that goes over the pump inlet. It's not a filter, but more of a FOD screen to keep any trash that makes its way into the fuel tank from jamming the pump.
The old pump will "bump" and try to start when hit with 12V, but won't continue. Usually when a fuel pump fails, it won't do anything when energized. This behavior makes me think that it sucked up some debris from inside the tank and got jammed.
Sooo.... I don't see any sock on the new pump. Am I missing something? Is there a screen or pre-filter inside the module?
Can I add a sock?

Tank goes back in next weekend, so I have a few days to figure this out.

[The Dark Side of Will]

Got the fuel tank in and figured out how to hook it up appropriately. Keyed on and heard the pump, though it didn't sound great since there was hardly any fuel in the tank. Poured 3 1/2 gallons of diesel in and the pump sounded better. I gave the pump some run time to bleed the lines, then tried to start. It was cranky and had several failed attempts. I was worried that it might have a high pressure pump problem, but it showed 6000 psi rail pressure cranking. After enough tries, it stayed lit, but had a miss. I brought it up to ~1800 RPM for a minute or two, then let it settle back down and it was hitting on all six. :grin2:

I poked the neutral button and it kicked back into 4Hi. Put it in gear and it moved... so far so good.

Naturally, the very next thing I did was some Jeep stuff:





I tried the hill where I took the in-process photo first. I tried to kick it into low range, but it dinged and flashed the "Service 4WD System" message, so I have some work to do there. My dad said it barely spun the right rear just a little bit climbing the hill it climbed and obviously spun all four on the hill that was too slippery, so the QD2 system works, which is good news.

It had zero rear shocks installed, and I bought Bilstein 33-225807's for the rear, BUT the sleeves are too wide! I @$$ume they install with the bodies down, but the gap where the top bushing installs is 1.625" wide, while the bushing sleeve is 1.812"! It's 3/16" too big! What the heck? Is this a normal problem?

[ericjon262]

Can't say on the shocks, but I can say it needs some mud terrains!

[The Dark Side of Will]

I'll just throw those Rubicon wheels back on the front!

It has a fuel leak somewhere in the rats' nest of piping on the top of the engine. Via a jumper to hot wire the lift pump, we're pretty sure it's on the low pressure side. High side plumbing is pretty darn reliable. I need to verify by jumping the lift pump and letting it run for about 10 minutes to see if I get fuel dripping off the bottom of the bellhousing next weekend. It takes that long because the fuel has to drip down over everything from the top of the engine. I suspect it's related to the fuel filter. I have a new one ready to go in. It uses the same fuel filter as the Benz, so that was easy.

I contacted Bilstein on their website. They said that sometimes WK's have problems if someone installed a cheap shock with the same mounts at both ends and just used the bolt to pull the mount in. I guess that means I just spread the shock mount until the shock fits.

I'm about to do a 200k transmission service on the Benz, to include installing AMG "blue top" solenoids. If that works out well, I'll put doing the same to this beast on the list.

Of course "The List" already includes rock sliders, skid plates, 2" rear lift, 17x8+ wheels, Duratracs

[The Dark Side of Will]

Here's what I'm dealing with on the shocks:

Bodies down, boots up is the usual way to install shocks. This puts the wide mount into the body mount. I can spread the body mount to fit, BUT... why should I have to? This is part number Bilstein lists for this app. It should bolt right in.
It's not just a little bit too wide, either. It's 3/16" too wide... it's WAY too wide.

The body end eye mount fits into bolt locations fine.

The boot end of the shock is too wide to go into either place it's supposed to go:

[The Dark Side of Will]

I got the shocks in over the weekend. I called Bilstein about the problem. They said that some bottom market shocks have the same eye on both ends, which means it's the wrong eye for the top. Installers typically just tighten down the bolt anyway, squeezing the top mount narrower than it should be. My dad and I used a long 12mm bolt, nut and a couple of washers. Put the bolt through the outboard cheek of the pocket, through the washers and nut in the pocket, then into the welded nut on the body. At that point, holding the bolt and "loosening" the nut pushed the cheek of the pocket back out where it should be. The Bilsteins then installed as they should. It drives MUCH better with rear shocks installed!



It had a fuel leak somewhere in the rats' nest of plumbing on top of the engine (Ooops... didn't get a pic). I jumpered the fuel pump and saw that the lip on top of the fuel filter filled up like a bowl fairly quickly, so the problem is obviously in the fuel filter plumbing. The fuel comes out of the pump assembly and into nylon lines on top of the tank. Those plug into hard lines on the body which come up the firewall to connect to braided stainless lines which go to the left valve cover, where they connect to hard lines on the engine. The supply hardline goes over the valve cover and under the turbo inlet piping to connect to 4-5" of 3/8" hose which goes to the filter inlet. The hose wasn't in bad shape, but wasn't in great shape. It could stand to be replaced after 211k, but has an Oetiker clamp on the hard line, so replacing it isn't so easy. It has a regular worm drive clamp on the filter, at least. The outlet from the filter is 5/16". The hose goes a few inches to a T, then about a foot of formed hose going to the HPP inlet. The injector return fuel connects to this T... so the injector return fuel gets mixed with fresh fuel and recycled back into the HPP. The HPP supplies the rail, which supplies the injectors with individual pipes. There's a regulator solenoid on the end of the rail which feeds the return line to the tank. There's something else I'm flaking on, because there's a junction block on the return line, but I don't remember what the other input is.
Anyway, it's a complicated fuel system, and max rail pressure is >20,000 PSI, although I haven't driven the vehicle hard enough to see it that high.

The water-in-fuel sensor is installed into the fuel filter. There's a plastic bleeder screw installed into the WiF sensor. It's literally just like a brake bleeder screw except it has an o-ring seal instead of a conical seat seal and a knob so it can be opened by hand (The fact that the engine cover is secured with hex screws rather than thumb screws makes for a fun conundrum). The WiF sensor projects through the middle of the filter down to the bottom, where it has two naked conductors and, of course, the bleed tube.
The new filter does not come with a new WiF sensor, but does come with new o-rings for the WiF sensor, as well as a replacement bleeder screw.
Here's the new Mann filter with WiF sensor installed. I compared the new one to the old and my first thought was, liiiiiiiiiiiiiiterally: " WTF, Mann?" Why is the new filter smaller than the old one?



The plastic turbo inlet tube has to come off to get the filter out.
The filter is in the V, of course. It sits on top of... some part of the engine block and has a cute little clamp thingy with mount tabs at the top holding it in place. There's a plastic booster seat holding it a little bit off the bottom of the well area shown here. There was a slightly smaller plastic booster seat around the reduced diameter of the old filter. I installed the new filter with both, which lifted its lip ~3/4" up from the clamp.
I then tried to reinstall the turbo inlet tube... which wouldn't fit with the filter that high. Of course I had disconnect all the connections to get it out to remove the second booster seat. The filter then sat all the way down with its lip in contact with the clamp. And the intake pipe went back in.



After I got the new filter all the way in, I checked the VNT actuator. On my Benz DD, the VNT actuator link rod had seized on the operating lever arm at the turbine housing end. Cleaning that pin up with scotchbrite and reassembling with anti-seize fixed that P0299 code. A quick check of actuator function is for one person to start the engine while someone else watches the actuator arm. On the OM648 in the Benz, the actuator arm cycles through its whole range of motion (90 degrees) and back when the engine starts. On the OM642, apparently it only goes one way... it went all the way down when my dad started the engine, then all the way back up when he shut it off. That appears to work. The next probable causes for the P0299 are boost leak and turbo malfunction. Boost leak is of course far more common.
I removed the actuator kind of for practice and kind of just to anti-seize the mounting bolts for future ease of removal.



On the test drive following this work, it set pending P0299 and went into reduced power mode basically as soon as I gave it enough throttle to exceed 45 mph. At least I've ruled out the VNT actuator as the problem. Can a clogged DPF cause this? That would set a code, right?

I used BlueDriver to read *ALL* the codes in all the vehicle's systems... 65 codes. I did not clear them at that time because I didn't read the report until later. Most were stored and related to some module can't communicate with some other module. There are only a few active ones, listed below. The active one in the 4WD system is "Transfer Case Clutches Worn", which is somewhat expected at 211,000 miles... but that's the only problem. After reading all the codes and trying to move the vehicle, I found that the T-case was in surprise neutral, which was weird. I poked the neutral button and it shifted into 4Lo, which was also weird, but indicated the range actuator works. I played with it in 4Lo a bit, then was able to coax it back into 4Hi... I shifted it back to 4Lo and back to 4Hi again, which worked fine. I don't know what was wrong with it last weekend, but apparently I don't need to buy an actuator, so that's fine. I'll clear all the codes next time I'm at my dad's house and see which ones come back.

It's coming together to DD status fix by fix. Having good shocks in the rear highlights that the front shocks are worn out, so that's another fun thing I need to do. I can also feel the steering vagueness and reduced self-centering due to loss of caster due to the Rough Country spacer lift as I drive it, so it needs corrective UCAs as well. There are at least two brands: JBA and Rocky Road, although they look exactly the same. Rocky Road modifies OE rubber bushings, while JBA includes 2 piece urethane bushings. I wonder if I can get the Lemforder Mercedes ball joint to fit... Hmm... These control arms aren't adjustable... they're just fixed with a different alignment than the OE ones. I may be able to re-use my 3/4" rod ends from my first attempt at adjustable upper arms for the Storm Trooper in order to build adjustable upper arms for the WKGC... Dammit... no I can't be going down that rabbit hole this soon!

Codes that I think are lighting things up on my dash:
Wireless Control Module:
C1501-C1504 TPMS Sensors (Not currently installed)

Park Assist Module
B122C PTS Sensor 7 Circuit Low
B122E PTS Sensor 7 Ring Time Too Short

Occupant Restraint Controller
U0176 Lost Communication w/ Right Side Satellite Acceleration Sensor 2

All Wheel/Final Drive
C1438 Transfer Case Differential Clutch Worn

Powertrain Control Module
P0299 Turbocharger Underboost

[ericjon262]

I don't know a ton about diesels, but I imagine anything that would cause differential pressure across the turbine to go down would also cause the turbo to make less boost. Do trouble codes exist for a clogged DPF? can you remove the DPF (temporarily) and see if the condition clears? I bought a $50 smoke test kit on ebay a while back, it's really good at helping find boost leaks.

[The Dark Side of Will]

I got to play with it a little more tonight. I cleared all 65 codes across the whole system, then took it for a drive.

Here's what came back up:

Wireless Module
C1501-C1504 TPMS sensors

Park Assist Module
B122C PTS Sensor 7 Circuit Low

Steering Column Module
B160A Panel Dimmer Input Circuit Low
(I think this has to do with the fact that the cruise control buttons on the steering wheel are not illuminated when the dash lights are on)

Occupant Restraint Controller
U0176 Lost Communication w/ Right Side Satellite Acceleration Sensor 2

Electronic Shifter Module
Stored:
P0607 Control Module Performance

All Wheel/Final Drive
C140F Transfer Case Range Position Sensor Erratic Performance

(This is probably why it doesn't want to shift into 4Lo)

Powertrain Control Module
Active:
P0299 Turbocharger Underboost

Stored:
P0402 EGR "A" Flow Excessive Detected
P0700 Transmission Control System (MIL Request)
P0627 Fuel Pump "A" Control Circuit/Open
U1132 Lost Communication with Generator

Transmission Control Module
Stored:
U0404 Implausible Data Received from ESM
P0710 Transmission Fluid Temperature Sensor "A" Circuit

Sooo... The P0607 and U0404 are probably just two sides of the same coin... and they're stored anyway.

The C140F probably explains my difficulty entering low range. A dude on Jeep Forum suggested the different size tires may have set the "T-Case Clutches Worn" code, which did not come back during this short on-road drive.

The P0627 probably was set when I had the fuel pump relay out to jumper the fuel pump and had the key on at the same time.

And of course the most problematic one right now is P0299, as that puts the vehicle into reduced power mode.
I was looking at live data and noticed that as the engine was idling <1000 ft above sea level, the MAP reading was 13.2 psi. I looked up the weather on my phone and the baro (weather station, not from the phone) was 29.76in. Hmmm. I drove around a little more and the MAP said 13.8 psi, but the baro hadn't changed. I also remember that the shop that failed to fix my Benz' P0299 threw a MAP sensor at the car... since they could bill me for it and the smoke test didn't find any problems. Looks like a MAP sensor may be the next step on the WKGC. RockAuto lists an "Intake Manifold Differential Sensor" which looks like a MAP referenced to something other than ambient. Hmmm...

https://www.rockauto.com/en/moreinfo.ph ... 43&jsn=965